Revert "Revert "Revert "Revert "Add implicit null and stack checks for x86""""
This reverts commit 0025a86411145eb7cd4971f9234fc21c7b4aced1.
Bug: 16256184
Change-Id: Ie0760a0c293aa3b62e2885398a8c512b7a946a73
diff --git a/runtime/fault_handler.cc b/runtime/fault_handler.cc
index b4355ca..1b91628 100644
--- a/runtime/fault_handler.cc
+++ b/runtime/fault_handler.cc
@@ -18,12 +18,9 @@
#include <sys/mman.h>
#include <sys/ucontext.h>
-
#include "mirror/art_method.h"
#include "mirror/class.h"
-#ifdef HAVE_ANDROID_OS
#include "sigchain.h"
-#endif
#include "thread-inl.h"
#include "verify_object-inl.h"
@@ -40,6 +37,7 @@
// Signal handler called on SIGSEGV.
static void art_fault_handler(int sig, siginfo_t* info, void* context) {
+ // std::cout << "handling fault in ART handler\n";
fault_manager.HandleFault(sig, info, context);
}
@@ -48,10 +46,6 @@
}
FaultManager::~FaultManager() {
-#ifdef HAVE_ANDROID_OS
- UnclaimSignalChain(SIGSEGV);
-#endif
- sigaction(SIGSEGV, &oldaction_, nullptr); // Restore old handler.
}
@@ -65,11 +59,12 @@
#endif
// Set our signal handler now.
- sigaction(SIGSEGV, &action, &oldaction_);
-#ifdef HAVE_ANDROID_OS
+ int e = sigaction(SIGSEGV, &action, &oldaction_);
+ if (e != 0) {
+ VLOG(signals) << "Failed to claim SEGV: " << strerror(errno);
+ }
// Make sure our signal handler is called before any user handlers.
ClaimSignalChain(SIGSEGV, &oldaction_);
-#endif
}
void FaultManager::HandleFault(int sig, siginfo_t* info, void* context) {
@@ -77,8 +72,12 @@
//
// If malloc calls abort, it will be holding its lock.
// If the handler tries to call malloc, it will deadlock.
+
+ // Also, there is only an 8K stack available here to logging can cause memory
+ // overwrite issues if you are unlucky. If you want to enable logging and
+ // are getting crashes, allocate more space for the alternate signal stack.
VLOG(signals) << "Handling fault";
- if (IsInGeneratedCode(context, true)) {
+ if (IsInGeneratedCode(info, context, true)) {
VLOG(signals) << "in generated code, looking for handler";
for (const auto& handler : generated_code_handlers_) {
VLOG(signals) << "invoking Action on handler " << handler;
@@ -94,11 +93,8 @@
}
art_sigsegv_fault();
-#ifdef HAVE_ANDROID_OS
+ // Pass this on to the next handler in the chain, or the default if none.
InvokeUserSignalHandler(sig, info, context);
-#else
- oldaction_.sa_sigaction(sig, info, context);
-#endif
}
void FaultManager::AddHandler(FaultHandler* handler, bool generated_code) {
@@ -125,7 +121,7 @@
// This function is called within the signal handler. It checks that
// the mutator_lock is held (shared). No annotalysis is done.
-bool FaultManager::IsInGeneratedCode(void* context, bool check_dex_pc) {
+bool FaultManager::IsInGeneratedCode(siginfo_t* siginfo, void* context, bool check_dex_pc) {
// We can only be running Java code in the current thread if it
// is in Runnable state.
VLOG(signals) << "Checking for generated code";
@@ -154,7 +150,7 @@
// Get the architecture specific method address and return address. These
// are in architecture specific files in arch/<arch>/fault_handler_<arch>.
- GetMethodAndReturnPCAndSP(context, &method_obj, &return_pc, &sp);
+ GetMethodAndReturnPCAndSP(siginfo, context, &method_obj, &return_pc, &sp);
// If we don't have a potential method, we're outta here.
VLOG(signals) << "potential method: " << method_obj;
@@ -235,12 +231,12 @@
bool JavaStackTraceHandler::Action(int sig, siginfo_t* siginfo, void* context) {
// Make sure that we are in the generated code, but we may not have a dex pc.
- if (manager_->IsInGeneratedCode(context, false)) {
+ if (manager_->IsInGeneratedCode(siginfo, context, false)) {
LOG(ERROR) << "Dumping java stack trace for crash in generated code";
mirror::ArtMethod* method = nullptr;
uintptr_t return_pc = 0;
uintptr_t sp = 0;
- manager_->GetMethodAndReturnPCAndSP(context, &method, &return_pc, &sp);
+ manager_->GetMethodAndReturnPCAndSP(siginfo, context, &method, &return_pc, &sp);
Thread* self = Thread::Current();
// Inside of generated code, sp[0] is the method, so sp is the frame.
StackReference<mirror::ArtMethod>* frame =